Free Brinell Hardness Calculator
Hardness Converter
Brinell hardness calculator and converter for Rockwell C (HRC), Rockwell B (HRB), Vickers (HV), and Brinell (HBW) scales using the ASTM E140 standard. Free, instant, mobile-friendly.
Convert Hardness Value
Common Mold Tool Steels
Reference table for tool steels commonly used in injection mold construction.
| Steel | DIN | HRC Range | Typical Use |
|---|---|---|---|
| P20 | 1.2311 | 28 to 34 | General purpose mold base, low volume production |
| P20+Ni (718) | 1.2738 | 28 to 36 | Larger molds, better polishability than P20 |
| H13 | 1.2344 | 44 to 52 | High production, die casting, hot runner components |
| S136 / 420SS | 1.2083 | 48 to 54 | Corrosive resins (PVC, POM), medical, optical |
| NAK80 | N/A | 38 to 42 | Pre-hardened, mirror polishable, medium production |
| S7 | N/A | 54 to 56 | Shock resistant, cam and lifter components |
| M2 (HSS) | 1.3343 | 60 to 65 | Wear inserts, gate inserts, high-wear areas |
| D2 | 1.2379 | 58 to 62 | Wear resistant inserts, trimming dies |
| A2 | 1.2363 | 57 to 62 | Trim steels, wear components |
| 2316 | 1.2316 | 28 to 34 | Pre-hardened stainless, corrosive materials |
Understanding Hardness Scales
Rockwell C (HRC)
The most common scale for hardened tool steels. Used for mold cores, cavities, and inserts. Range: 20 to 68 HRC. Higher values indicate harder, more wear resistant steel.
Rockwell B (HRB)
Used for softer steels and non-ferrous metals. Typical range: 70 to 100 HRB. Common for pre-hardened mold bases like P20 in the as-received condition.
Vickers (HV)
A versatile scale that works across a wide hardness range. Uses a diamond pyramid indenter. Particularly useful for thin sections and surface hardness measurements.
Brinell (HBW)
Uses a tungsten carbide ball indenter. Best for softer materials and large parts. The 3000 kg load is standard for steels. Good for verifying incoming mold base hardness.
Brinell Hardness Calculator FAQ
Common questions about Brinell conversion
What is a Brinell hardness calculator?
A Brinell hardness calculator converts between the Brinell hardness scale (HBW) and other hardness scales like Rockwell C (HRC), Rockwell B (HRB), and Vickers (HV) using the ASTM E140 conversion standard. It's used by metallurgists, mold makers, and quality engineers to interpret hardness test results across different testing methods on the same drawing or material certification.
How do you convert Brinell (HBW) to Rockwell C (HRC)?
There is no exact mathematical formula — conversion uses lookup tables defined in ASTM E140. As approximations for non-austenitic steels: HBW 229 ≈ HRC 20, HBW 400 ≈ HRC 42, HBW 600 ≈ HRC 56, HBW 700 ≈ HRC 62. For values between these points, linear interpolation gives a reliable estimate. Enter any value between HBW 229 and HBW 739 into the calculator above for an instant conversion.
What's the difference between Brinell and Rockwell hardness?
Brinell (HBW) uses a 10mm tungsten carbide ball pressed into the material with a 3000 kg load, then measures the diameter of the indent. Rockwell C (HRC) uses a 120° diamond cone with a 150 kg load and measures depth of penetration. Brinell is better for softer materials, castings, and large parts; Rockwell is faster and better for hardened tool steels and thin sections like inserts.
What is the valid range for Brinell to Rockwell conversion?
ASTM E140 conversions for non-austenitic steels are valid from approximately HBW 229 (HRC 20) up to HBW 739 (HRC 68). Below HBW 229, use the Rockwell B (HRB) scale instead — our calculator handles HRB 70 to 100 separately. Above HBW 739, the Brinell ball begins to deform and Rockwell C should be used directly.
Why use a hardness conversion calculator instead of testing directly?
Direct hardness testing in the correct scale is always preferred for critical applications. A conversion calculator is useful when: (1) you have hardness data from one test method but need to specify hardness in another scale on a drawing, (2) you're comparing supplier hardness certifications that use different scales, or (3) you're estimating whether a steel is at the right hardness for a given application. For ASTM-compliant material certifications, always test directly in the scale specified by your material spec.
Choosing the Right Steel?
Expert Steel Selection Guidance
The right steel choice affects mold life, cycle time, and total cost of ownership. Our engineers can recommend the optimal steel grade for your application.